Printing



Jul 14, 1935. c, CRAFTS zmwsv PRINTING Filed Sept. 9-; 1933 a II Y m 1/ mm W w mwwmy [I Patented July 14, 1936 PATENT I OFFICE PRINTING Curtis S. Crafts, Oak Park, 111., assignor to The Goss Printing Press Company, Chicago, 111., a

corporation of Illinois Application September 9, 1933, Serial No. 688,741

10 Claims.

The present invention relates to printing 4 presses and more particularly to a novel and improved means for securing and retaining stereotype printing plates on the plate cylinders of high speed rctary newspaper presses.

Objects and advantages of the invention will be set forth in part hereinafter and in part will be obvious herefrom, or may be learned by practice with the invention, the same being realized and attained by means of the instrumentalities and combinations pointed out in the appended claims.

The invention consists in the novel parts, constructions, arrangements, combinations and improvements herein shown and described.

The accompanying drawing, referred to herein and constituting a part hereof, illustrates one embodiment of the invention, and together with the description, serves to explain the principles of the invention.

Of the drawing:

Figure 1 is a vertical section of an illustrative embodiment of the present invention; and

Figure 2 is a fragmentary side elevation of the printing cylinder shown in Figure 1.

The present invention has for its object the provision of a novel and improved plate securing means adapted to secure stereotype printing plates on the printing cylinders of a high speed rotary newspaper press. A further object of the invention is the provision of such plate securing means permitting the cylinders to be run at extremely high speeds without buckling of the plate. Another object is the provision of a plate securing means constantly subjecting the stereotype plate to a stretching action during the operation of the press.

Referring now in detail to the illustrative embodiment of the invention, a printing cylinder I is provided which may be a plurality of pages long, as is customary in newspaper printing, and is adapted to receive and have secured to it a plurality of semi-cylindrical stereotype printing plates II, which may be arranged relatively to each other in the conventional manner.

Plates II are preferably formed near their leading and trailing edges with a plurality of narrow, shallow, undercut recesses l2 which are preferably axially alined, and may be positioned a predetermined distance from the leading or trailing edge l3, Id of the plate.

Means are provided for securing the plate to the cylinder near its leading edge, and for driving the plates, and comprise a plurality of clips l5 which are axially alined and more or less evenly spaced along the width of the plate, and are fixed in the cylinder, projecting slightly from the surface thereof. Clips H) are formed with a forwardly projecting portion l6 adapted to engage with the forward edge of undercut recess l2.

Means are also provided for securing the trail- 5 ing edge of the plate to the cylinder and for tensioning the plate during the printing operation and taking up any stretch, and for this purpose the cylinder is provided with a plurality of axially alined, relatively'deep recesses l0 l1, through which pass a shaft l8 journalled in the cylinder body between the recesses l'l. Shaft I8 is rotatable and to it are keyed a plurality of movable clips l9 adapted to be oscillated by movement of the shaft l8 and projectable rearwardly beyond the surface of the cylinder into engagement with the undercut wall of recesses l2. For resiliently urging the movable clips [9 rearwardly with respect to the rotation of the cylinder, the clips I9 are provided with individual spring means each comprising a compression spring 20 having one end seated in a small recess 2| at the bottom of recess l1 and having its other end seated in a cup 22 pivotally connected with a lug 23 projecting from the for- 25 ward side of clipwtil. Springs 20 are preferably quite strong and urge the outer hook-like ends 24 of clips [9 rearwardly with suflicient force to overcome the centrifugal force acting to move the trailing edge of the plate away from the cylinder.

For releasing all of the clips 19 at one time, when it is desired to change the plates on the cylinder, one end of the shaft I8 projects from the end of the cylinder l0 and is squared to receive an operating wrench, or may be otherwise actuated, to compress the springs 20 and thereby release the rear end of the plate H, after which the rear end of the plate and then the forward end may be lifted away from the cylinder.

In the operation of the conventional type of plate clamping means,v the pressure of the impression cylinder against the plate while printing causes a slight buckle or wrinkle to be formed in the plate which is rolled out rearwardly of the plate as the cylinders rotate. This rapidly repeated wrinkling or buckling of the plate gradually causes the leading end of the plate to be -worked free of the cylinder, destroying the lit a source of serious inJury to the mechanism and operators.

Furthermore, the plates have been maintained under compression axially of the cylinder, with no means for holding the central part 01. the plate to the cylinder against centrifugal force,

consequently the central part of the plate bulged beyond the side edges thereof.

In accordance with the present invention, there is no tendency for the plate to buckle or wrinkle, inasmuch as the plate is constantly subjected to a stretching action circumrerentially of the cylinder which maintains the plate always under tension.

Preferably, the recesses l2 in the plate do not extend all the way across, but are relatively narrow and positioned to engage with the several plate securing clips. Furthermore, the recesses at each end of the plate are uniformly spaced from the end so that the plate is symmetrical and may be reversed on the cylinder, as required by the imposition desired.

The invention in its broader aspects is not limited to the specific mechanisms shown and described but departures may be made therefrom within the scope or the accompanying claims without departing from the principles of the invention and without sacrificing its chief advantages.

What I claim is:

1. A printing cylinder for rotary newspaper presses including in combination a cylindrical body adapted to support a rigid printing plate, fixed plate securing means engageable with the under side of the plate near its forward end, movable plate securing means spaced apart axially of the cylinder and projecting through the surface of the cylinder so as to be engageable with the under side or the plate near its rear end and means for resiliently urging said plate securing means relatively away from each other.

2. A printing cylinder for rotary newspaper presses including in combination a cylindrical body adapted to support a curved stereotype printing plate having recesses near its leading and trailing edges, clips mounted on said cylinder engageable with said recesses, means for resiliently urging said clips relatively away from each other and means at one end of the cylinder for relatively moving said clips towards each other.

3. A printing cylinder for rotary newspaper presses including in combination a cylindrical body adapted to support a curved stereotype printing plate having recesses near its leading and trailing edges, clips mounted on said cylclips projecting through apertures in the cylinder surface and engageable with the recesses along the other edge, a common shaft Journalled in said cylinder and on which the movable clips are mounted and means for resiliently urging 5 the movable clips away from the fixed clips.

5. A printing cylinder for a high speed rotary press including in combination a cylindrical body adapted to support a rigid, curved stereotype printing plate having access along its leading and trailing edges, fixed clips engageable with the recesses along the leading edge, movable clips engageable with the recesses along its trailing edge, a common shaft journalled in its cylinder and on which the movable clips are mounted and means for resiliently urging the movable clips rearwardly with respect to the rotation oi. the cylinder.

6. In combination, a stereotype plate cylinder, means for securing a stereotype plate to the cylinder along its leading end, and a plurality of spaced apart devices engaging the trailing end of the plate and individually exerting resilient pressure at said separated points to tension the plate about the cylinder from the leading end to the trailing end.

7. In combination, a stereotype plate cylinder, means for securing a stereotype plate to the cylinder along its leading end, and a plurality of spaced apart devices engaging the trailing end of the plate and spring means operating on the individual devices to exert resilient pressure at said separated points to tension the plate about the cylinder from the leading end to the trailing end.

8. In combination, a stereotype plate cylinder, means for securing a stereotype plate to the cylinder along its leading end, and means for exerting live resilient pressure to tension the plate about the cylinder from the leading end to the trailing end, including a shaft journaled in the cylinder, plate engaging means mounted on the shaft and means for exerting continuous resilient pressure on the plate engaging means.

9. In combination, a stereotypeplate cylinder, means for securing a stereotype plate to the cylinder along its leading end, and means for exerting live resilient pressure to tension the plate about the cylinder from the leading end to the trailing end, including a shaft journalled in the cylinder, a plurality of plate-engaging devices mounted on the shaft, and a plurality oi resilient devices for exerting continuous resilient pressure on the individual plate-engaging devices.

10. The method of maintaining a stereotype printing plate on a plate cylinder in good printing condition at high operating speeds including securing the stereotype plate to the cylinder along its leading end, and resiliently stretching the plate around the cylinder from the leading end to the trailing end and also from the printing line to the trailing end during printing to eliminate wrinkling of the plate as it is subjected to pressure during printing.

CURTIS S. CRAFTS. 

